Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/04—Liquid carbonaceous fuels essentially based on blends of hydrocarbons
  • C10L1/08—Liquid carbonaceous fuels essentially based on blends of hydrocarbons for compression ignition

Definitions

• the present invention relates to a fuel composition suited for compression ignition engines, particularly to racing fuels.
• Fuel compositions suited for compression ignition engines are well known and are sometimes also referred to as diesel fuel.
• Diesel fuel compositions are disclosed in WO-A-03/004588 and EP-A-1 619 232 .
• When formulating the best fuel for such a race one will have to meet minimum requirements regarding the power of the fuel and the volumetric fuel consumption. Power is evidently important for a racing fuel.
• the volumetric fuel consumption is, however, also important because it will determine the number of required pit stops during the race.
• a fuel composition according to the present invention comprises a hydrocarbon blend having a cetane number of at least 62, a kinematic viscosity at 40°C of greater than 3.0 cSt (mm 2 / s) and a density at 15°C of greater than 830 kg/m 3 , wherein the Wear Scar value of the fuel composition is below 350 microns ( ⁇ m) as determined by CEC-F-06-A-96, and wherein the fuel composition comprises (b) a paraffinic fuel prepared by means of a Fischer-Tropsch condensation process, boiling in the gas oil range comprising more than 90 wt% paraffins and having a cetane number of between 70 and 85 in combination with (a) a mineral derived gas oil having a density at 15°C of between 800 and 860 kg/m3 and a kinematic viscosity at 40°C of between 1.5 and 15 cSt (mm2
• the fuel composition preferably has a density at 15°C of below 845 kg/m 3 .
• the cetane number as measured according to DIN 51773, is preferably at least 63.
• the upper limit of the cetane number will be determined by the compositional constraints of the base fuels used to formulate such a composition and the cetane improver additives present in the formulation. A practical upper limit will be 80.
• the aromatic content, as determined by IP 391, will typically be below 30 wt% and preferably less than 20 wt %. Compositions having between 5 and 20 wt% of aromatics have been found suited as racing fuel.
• the content of di/tri and poly-aromatics in the composition as determined by IP 391 is preferably less than 11% and more preferably less than 5%.
• the pour point, cloud point and cold filter plugging point (CFPP) of the fuel composition will depend on the climate conditions in which the fuel composition will be used. The values for all these properties may range from minus 40°C to +5°C.
• the fuel composition will suitably have a 90 %v/v distillation temperature (T90) of from 300 to 370°C, preferably below 360°C and more preferably between 310 and 360°C.
• T90 90 %v/v distillation temperature
• the kinematic viscosity at 40°C is preferably less than 4.5 cSt (mm 2 /s) in order to meet the governmental specifications.
• the fuel composition comprises one or more additives.
• suitable additives are lubricity enhancers; dehazers, e.g. alkoxylated phenol formaldehyde polymers; anti-foaming agents (e.g. polyether-modified polysiloxanes); ignition improvers (cetane improvers) (e.g. 2-ethylhexyl nitrate (EHN), cyclohexyl nitrate, di-tert-butyl peroxide and those disclosed in US-A-4208190 at column 2, line 27 to column 3, line 21); anti-rust agents (e.g.
• a propane-1,2-diol semi-ester of tetrapropenyl succinic acid, or polyhydric alcohol esters of a succinic acid derivative the succinic acid derivative having on at least one of its alpha-carbon atoms an unsubstituted or substituted aliphatic hydrocarbon group containing from 20 to 500 carbon atoms, e.g. the pentaerythritol diester of polyisobutylene-substituted succinic acid); corrosion inhibitors; reodorants; anti-wear additives; anti-oxidants (e.g.
• phenolics such as 2,6-di-tert-butylphenol, or phenylenediamines such as N,N'-di-sec-butyl-p-phenylenediamine); metal deactivators; and combustion improvers.
• detergents suitable for use in fuel additives for the present purpose include polyolefin substituted succinimides or succinamides of polyamines, for instance polyisobutylene succinimides or polyisobutylene amine succinamides, aliphatic amines, Mannich bases or amines and polyolefin (e.g. polyisobutylene) maleic anhydrides.
• Succinimide dispersant additives are described, for example, in GB-A-960493 , EP-A-0147240 , EP-A-0482253 , EP-A-0613938 , EP-A-0557516 and WO-A-98/42808 .
• Particularly preferred are polyolefin substituted succinimides such as polyisobutylene succinimides.
• the fuel composition comprises a lubricity enhancer additive in order to improve the Wear Scar value (HFRR) of the fuel.
• the content of lubricity additive is such that the Wear Scar value of the fuel composition has a resultant value of below 300 microns ( ⁇ m).
• the content of lubricity additive needed to achieve such values will depend on the lubricity of the base fuels used to formulate the fuel composition according to the present invention. It is found that especially in fuel compositions wherein the sulphur content is lower than 500 ppmw, the lubricity additive is preferably present at a concentration of between 50 and 1000 ppmw, preferably between 100 and 1000 ppmw.
• Suitable commercially available lubricity enhancers include ester- and acid-based additives.
• Other lubricity enhancers are described in the patent literature, in particular in connection with their use in low sulphur content diesel fuels, for example in: - the paper by Danping Wei and H.A.
• the fuel composition as described above having the unique combination of a relatively high density and viscosity in combination with a relatively high cetane number may be suitably obtained by blending (b) a paraffinic fuel boiling in the gas oil range with (a) a mineral derived gas oil and with (c) a naphthenic rich blending component boiling in the gas oil range.
• the present invention is directed to a fuel composition
• a fuel composition comprising a hydrocarbon blend having a cetane number of at least 62, a kinematic viscosity at 40°C of greater than 3.0 cSt and a density at 15°C of greater than 830 kg/m 3
• the fuel composition comprises (b) a paraffinic fuel boiling in the gas oil range comprising more than 90 wt% paraffins and having a cetane number of between 70 and 85 in combination with (a) a mineral derived gas oil having a density at 15°C of between 800 and 860 kg/m 3 and a kinematic viscosity at 40°C of between 1.5 and 15 cSt (mm 2 /s) and (c) a naphthenic rich blending component boiling in the gas oil range having a density at 15°C of greater than 860 kg/ m 3 and having a pour point of below -30°C, the Wear Scar value of said fuel composition is below 350 microns as determined by CEC
• Component (a) is a mineral derived gas oil.
• a gas oil boiling in the gas oil range, will preferably have an aromatics content of below 30 wt%.
• Such mineral derived gas oil products may be straight run derived distillate fractions from a mineral crude source or from a gas condensate source or the products of a refinery fuels hydrocracker. The straight run fractions are preferably subjected to a de-sulphurization step in order to reduce the sulphur content to a level suited to meet the local requirements. Due to the preferred aromatics content the density will suitably be between 800 and 860 kg/m 3 .
• the cetane number may range from 40 to 65.
• kinematic viscosity at 40°C (ASTM D445) might suitably be from 1.5 to 15 cSt (mm 2 /s). It may appear that the above property ranges for the mineral gas oil components overlap the properties of the fuel composition. However, no mineral gas oil products are known to have the specific combination of density, viscosity and cetane number of the fuel composition according to the present invention.
• Component (b) is a paraffinic fuel.
• a paraffinic fuel in the context of the present invention is meant a composition comprising more than 90 wt% paraffins and more preferably more than 95 wt% paraffins.
• the iso to normal ratio of the paraffins as present in the paraffinic fuel is preferably greater than 0.3, more preferably greater than 1, even more preferably greater than 3.
• the paraffinic fuel may comprise substantially only iso-paraffins.
• the iso to normal ratio and the paraffin content of the paraffinic fuel in the context of the present invention are measured by means of comprehensive multidimensional gas chromatography (GCxGC), as described in P.J. Schoenmakers, J.L.M.M. Oomen, J. Blomberg, W. Genuit, G. van Velzen, J. Chromatogr. A, 892 (2000) p. 29 and further.
• GCxGC gas chromatography
• the paraffinic fuel suitably has a density from 760 to 790 kg/m 3 at 15°C; a cetane number (DIN 51773) greater than 70, suitably from 74 to 85; a kinematic viscosity from 2.0 to 4.5, preferably from 2.5 to 4.0, more preferably from 2.9 to 3.7, cSt (mm 2 /s) at 40°C; and a sulphur content of 5 ppmw (parts per million by weight) or less, preferably of 2 ppmw or less.
• the paraffin gas oil component is prepared by means of a Fischer-Tropsch condensation process.
• the carbon monoxide and hydrogen may themselves be derived from organic or inorganic, natural or synthetic sources, typically either from coal, biomass, for example wood chips and organic waste, bituminous oils, natural gas or from organically derived methane.
• a gas oil product may be obtained directly from this reaction, or indirectly for instance by fractionation of a Fischer-Tropsch synthesis product or from a hydrotreated Fischer-Tropsch synthesis product.
• Hydrotreatment can involve hydrocracking to adjust the boiling range (see, e.g. GB-B-2077289 and EP-A-0147873 ) and/or hydroisomerisation, which can improve cold flow properties by increasing the proportion of branched paraffins.
• EP-A-0583836 describes a two-step hydrotreatment process in which a Fischer-Tropsch synthesis product is firstly subjected to hydroconversion under conditions such that it undergoes substantially no isomerisation or hydrocracking (this hydrogenates the olefinic and oxygen-containing components), and then at least part of the resultant product is hydroconverted under conditions such that hydrocracking and isomerisation occur to yield a substantially paraffinic hydrocarbon fuel.
• the desired gas oil fraction(s) may subsequently be isolated for instance by distillation.
• the paraffinic gas oil is preferably obtained in a process which involves a step where the paraffins are catalytically isomerized, to a substantially 100% isoparaffinic fuel, in the presence of a suitable catalyst comprising a medium pore size zeolite and a noble metal hydrogenation component. It has been found that the gas oils as obtained have excellent lubricity values. This would allow the formulator of the fuel composition to use less of the lubricity additive. An example of a process to make such a paraffinic gas oil component is described in WO-A-03/070857 .
• Typical catalysts for the Fischer-Tropsch synthesis of paraffinic hydrocarbons comprise, as the catalytically active component, a metal from Group VIII of the periodic table, in particular ruthenium, iron, cobalt or nickel. Suitable such catalysts are described for example in EP-A-0583836 (pages 3 and 4).
• SMDS Fischer-Tropsch based process
• This process also sometimes referred to as the ShellTM “Gas-to-Liquids” or “GTL” technology
• ShellTM Middle distillate range products by conversion of a natural gas (primarily methane) derived synthesis gas into a heavy long-chain hydrocarbon (paraffin) wax which can then be hydroconverted and fractionated to produce liquid transport fuels such as the gas oils useable in diesel fuel compositions.
• a version of the SMDS process utilising a fixed-bed reactor for the catalytic conversion step, is currently in use in Bintulu, Malaysia and its products have been blended with petroleum derived gas oils in commercially available automotive fuels.
• Gas oils prepared by the SMDS process are commercially available from Shell companies. Further examples of Fischer-Tropsch derived gas oils are described in EP-A-0583836 , EP-A-1101813 , WO-A-97/14768 , WO-A-97/14769 , WO-A-00/20534 , WO-A-00/20535 , WO-A-00/11116 , WO-A-00/11117 , WO-A-01/83406 , WO-A-01/83641 , WO-A-01/83647 , WO-A-01/83648 and US-A-6204426 .
• a Fischer-Tropsch derived gas oil has essentially no, or undetectable levels of, sulphur and nitrogen. Compounds containing these heteroatoms tend to act as poisons for Fischer-Tropsch catalysts and are therefore removed from the synthesis gas feed. Further, the process as usually operated produces no or virtually no aromatic components.
• the aromatics content of a Fischer-Tropsch gas oil will typically be below 1%w/w, preferably below 0.5%w/w and more preferably below 0.1%w/w.
• Component (c) is a naphthenic component.
• the naphthenic blending component will comprise a large content of naphthenic components boiling in the gas oil range. Because of this feature the density will be above 860 kg/m 3 .
• Another typical property of the preferred naphthenic blending component is the low pour point.
• the pour point of the blending component is below -30°C and more preferably below -40°C.
• the content of aromatic compounds is preferably below 30 wt%, more preferably below 20 wt% according to IP 391. Due to the low contribution to the cetane number of naphthenic compounds, the cetane number will be typically lower than 50.
• the kinematic viscosity at 40°C of the naphthenic blending component is preferably between 6 and 30 cSt (mm 2 /s).
• Naphthenic blending components may be derived from so-called naphthenic crude sources, by hydrogenation of light cycle oils as obtained in a catalytic cracking process.
• the naphthenic compounds may be made by means of a synthetic route.
• suitable naphthenic blending components are the commercially available products named 'Shell Oil 4308' as obtainable from Deutsche Shell GmbH.
• the fuel composition according to the present invention is particularly applicable where the fuel composition is used or intended to be used in a direct injection diesel engine, for example of the rotary pump, in-line pump, unit pump, electronic unit injector or common rail type, or in an indirect injection diesel engine.
• the fuel composition may be suitable for use in heavy and/or light duty diesel engines. It has been found that the fuel composition is particularly suited for use as a racing fuel in any one of the above engines.
• the present invention is also directed to the use of the fuel composition of the present invention to run a diesel powered car in a race which lasts between 5 and 30 hours, wherein the engine can be any of the above described engines, in particular in a race car equipped with a turbocharged direct injection diesel engine and equipped with a so-called advanced common rail injection system working at a rail pressure of above 1600 bar.
• This example illustrates the effects on the responsiveness of a first engine using Fischer-Tropsch derived diesel fuel.
• Fuel compositions were made using the four blending components listed in Table 1: TABLE 1 Fuel property Mineral gas oil component (a) Fischer-Tropsch derived fuel (b1) Fischer-Tropsch derived fuel (b2) Naphthenic blending component (c) Standard Diesel Density @ 15°C (ASTM D4502), kg/m 3 840 779 785 879 827 Cloud Point (DIN EN 23015), °C -5 -17 0 ⁇ -50 -7 Pour point (DIN EN ISO 3016), °C nd- nd- -2 ⁇ -50 - Distillation Initial boiling point, °C 191 206 212 282 163 T50, °C 275 272 297 308 258 T90, °C 331 310 343 332 338 Final boiling point, °C 356 321 357 349 364 Cetane number (DIN 51773) 57.5 74.2 79.7 43.7 53.9 Kinematic viscosity @ 40°C (DIN EN ISO 3104), mm 2
• blends F1, F2, F3, F4, F5 and F6 were compared, blends F3 and F4 being according to the present invention. All blends contained the same additive package, typical for a premium diesel engine fuel, and 250 ppmw of a lubricity additive. Details of these blends are shown in Table 2: TABLE 2 Description Blend No.
• F1 F2 F3 F4 F5 F6 Component a Vol% 80 69.0 62.0 49.0 66.0 87.0 Component b1 Vol% 20 6.25 6.25 7.5 5.25 3.25 Component b2 Vol% 0 18.75 18.75 22.5 15.75 9.75 Component c Vol% 0 6.0 13.0 21.0 13.0 0 Cetane number - 59.7 63.2 63.0 63.2 60.3 60.4 Kinematic viscosity @40°C cSt (mm 2 /s) 3.1 3.3 3.5 3.7 3.5 3.2 Total Aromatics Wt% 17.4 16.3 15.9 14.6 17.2 19.0 Di/Tri/Poly Aromatics Wt% 2.2 1.9 1.8 1.6 1.9 2.2 Density @15°C kg/m 3 828.0 828.6 831.3 831.7 833.6 833.0 Cloud Point °C -7 -6 -6 -7 -5 -6 CFPP °C -9 -8 -10 -9 -8 -9 Pour Point °
• Fuel F3 of Table 2 has also been compared with a Standard Diesel of Table 1 in a BMW 320d having the specifications as listed in Table 4.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Liquid Carbonaceous Fuels (AREA)
• Lubricants (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

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• 2007
  • 2007-03-06 AR ARP070100914A patent/AR059751A1/es unknown
  • 2007-03-08 US US11/683,895 patent/US8541635B2/en not_active Expired - Fee Related
  • 2007-03-09 SG SG2011072881A patent/SG175594A1/en unknown
  • 2007-03-09 BR BRPI0708703-9A patent/BRPI0708703A2/pt not_active Application Discontinuation
  • 2007-03-09 PL PL07726736.7T patent/PL1994128T3/pl unknown
  • 2007-03-09 MY MYPI20083495A patent/MY154777A/en unknown
  • 2007-03-09 EP EP07726736.7A patent/EP1994128B1/en not_active Not-in-force
  • 2007-03-09 WO PCT/EP2007/052213 patent/WO2007104709A1/en not_active Ceased
• 2008
  • 2008-10-09 NO NO20084241A patent/NO20084241L/no not_active Application Discontinuation

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